NIC Processor using variable precision block quantization

Claim 3

The apparatus of claim 1 wherein each of said N samples are represented by a plurality of bits in a data compressed format having a predetermined number of segments, and wherein said bit number determining means examines a group of bits from said maximum value, the number of bits in said group being the minimum number of bits which can be used to uniquely identify each of said segments.

Claim 4

The apparatus of claim 2 wherein said bit number determining means comprises a memory device receiving said group of bits from said maximum value for determining said bit number in accordance with said group of bits.

Claim 5

The apparatus of claim 3 wherein said group of bits consists of three bits, and said bit number is one of 2, 4 and 6 bits, excluding said sign bits.

Claim 6

The apparatus of claim 4 wherein said group of bits are taken from the most significant magnitude bits in said maximum value, and said memory device provides the input/output function: ______________________________________ Group of Bits Bit Number Excluding Sign Bit ______________________________________ 0 0 0 2 0 0 1 2 0 1 0 2 0 1 1 2 1 0 0 4 1 0 1 4 1 1 0 6 1 1 1 6. ______________________________________

Claim 8

The apparatus of claim 6 wherein said step size determining means comprises a divider for dividing said maximum value by a power of 2 to produce said quantizing step size.

Claim 9

The apparatus of claim 7 wherein said power of 2 is equal to 2.sup.n i.sup.-1, where n i -1 represents said bit number excluding said sign bits.

Claim 12

The apparatus of claim 9 comprising sample length determining means responsive to said extracted protocol information to provide sample length information to said sample forming means indicating the number of bits in each sample in accordance with said value of said largest of said N samples.

Claim 13

The apparatus of claim 10 wherein said decoder decodes each of said N digital samples as a function of (i) the value of each of said N samples, (ii) said value of the largest of said N samples, and (iii) the value of said number of bits in each sample.

Claim 14

The apparatus of claim 11 wherein said decoder decodes said N digital samples in accordance with the function: S.sub.j =[2(M-1)+1]S.sub.max /2.sup.n i, where S j =the decoded value, M-1=the value of the associated digital sample produced by said sample forming means, S max =the value of said largest of said N samples, and n i= the length in bits of said associated digital sample.

Claim 15

A process for encoding a block of N digital samples having sign and magnitude bits, the process comprising: finding the maximum value of said N samples; determining the number of bits to be used in encoding said N samples as a function of said maximum value; determining a quantizing step size for said N samples as a function of said maximum value; quantizing said samples according to said determined quantizing step size to obtain quantized values; and encoding said quantized values to produce N encoded samples each having said determined number of bits.

Claim 16

A process for encoding a block of N digital samples having sign and magnitude bits, the process comprising: finding the maximum value of said N samples; determining the number of bits to be used in encoding said N samples as a function of said maximum value; determining a quantizing step size for said N samples as a function of said maximum value; quantizing said samples according to said determined quantizing step size to obtain quantized values; and encoding said quantized values to produce N encoded samples each having said determined number of bits.

Claim 17

The method of claim 13 wherein said N digital samples are each represented by a plurality of bits in a compressed format having a predetermined number of segments, said step of determining said number of bits comprising examining a group of bits from said maximum value, the number of bits being examined corresponding to the minimum number of bits which can be used to uniquely identify each of said segments.

Claim 18

The method of claim 14 wherein said number of examined bits is three bits and said step of determining said number of bits further comprises selecting the number of said bits to be used in encoding said samples to be equal to one of 2, 4 and 6 bits, excluding sign bits.

Claim 19

The method of claim 15 wherein said selecting step comprises selecting the bit number excluding said sign bit as a function of the value of said group of bits as follows: ______________________________________ Group of Bits Bit Number Excluding Sign Bit ______________________________________ 0 0 0 2 0 0 1 2 0 1 0 2 0 1 1 2 1 0 0 4 1 0 1 4 1 1 0 6 1 1 1 6 ______________________________________

Claim 21

The method of claim 17, wherein said step of determining said quantizing step size comprises dividing said maximum value by a power of 2 to produce said quantizing step size.

Claim 22

The method of claim 18 wherein said power of 2 is equal to 2.sup.n i.sup.-1, where n i -1 represents said determined bit number excluding sign bits.

Claim 25

The method of claim 20 wherein said forming step includes the step of determining the number of bits in said samples in response to said extracted protocol information, and forming said N digital samples in accordance with said determined number of bits.

Claim 26

The method of claim 21 wherein said decoding step comprises decoding each of said N digital samples as a function of (i) the value of said each sample, (ii) the value of the largest of said N samples, and (iii) the value of said determined number of bits.

Claim 27

The method of claim 22 wherein said decoding step comprises decoding each of said N digital samples in accordance with the function S.sub.j =[2(M-1)+1]S.sub.max /2.sup.n i, where S j =the decoded value, M-1=the value of said each digital sample, S max =the value of said largest of said N samples, and n i =said determined number of bits.